MECHANICS AND USEFUL ARTS. 81 



is necessarily limited to the exterior, as deep impregnation ig 

 stopped by the newly formed products. Moreover, the cost is 

 high, and the salts more or less injuriously aflfect the wood sub- 

 stance. 



"My discovery consists in simply treating the wood with a 

 boiling solution of borax in water, which easily and elfectually 

 dissolves and removes all those perishable substances, without 

 injuriously affecting the wood fibre, which, on the contrar}'-, be- 

 comes harder, impregnable to water, vermin-proof, perfectly in- 

 different to the moisture or dryness of the atmosphere, and almost 

 incombustible. 



"The process and operation are as follows: In a tank, of 

 wood or iron, I prepare a saturated or nearly saturated solution 

 of borax in water, sufficient to cover the wood. I then raise the 

 temperature, by steam or otherwise, to the boiling-point, and 

 keep it there from 2 to 12 hours, according to the porosity and 

 thickness of the wood. I then repeat this operation in a freshly 

 concentrated solution of borax in water, but immersing the wood 

 only half as long as before. The wood is then taken out, and, as 

 soon as dry, it is ready for use, if its hardness and discoloration 

 are not objectionable ; or it may be several times washed in boil- 

 ing water, which will extract the absorbed borax in connection 

 with the colored matter, and restore its former color and appear- 

 ance, more or less, at will. 



"It is not necessary to use a very strong solution, but I prefer 

 it on account of the facility for re-using it. 



" Simple as my process is, it may be advantageously altered iu 

 some cases. When thick lumbers are to be treated, it is well to 

 steam them thoroughly in the ordinary way, and place them in 

 the tank while still warm and wet. The denser and heavier 

 liquid of the borax solution will more quickly penetrate the pores 

 of the wood, and shorten the operation considerably. 



" If it be desirable to imi^regnate the wood with tar, coal-oil, 

 or like substances, they are easily applied after the wood has 

 been thoroughly dried. 



" If it be desirable to make the wood perfectly water-tight, 

 shellac, or other gum, or resin, or substance soluble in a boiling 

 solution of borax, and insoluble, after drying, in cold water, may 

 be added to the liquid of the second operation." 



WOOD-HANGINGS FOR WALLS. 



At a recent meeting of the Massachusetts Institute of Tech- 

 nology, was exhibited an extensive series of specimens of the 

 " wood-hangings " recently introduced as substitutes for paper on 

 the walls of houses. 



The machinery used in preparing this wood is that used in 

 cutting veneers, but the sheets cut are much thinner than any 

 veneers, some of them being as thin and delicate as tissue paper, 

 2 to 300 thicknesses to an inch, though the common tliickness 

 is from 110 to 120 to the inch. The logs are steamed before they 



